The present invention relates to a display device, and, more particularly, to a display device and a method of driving a display device so as to achieve high luminance and excellent motion picture display characteristics.
Flat panel type display devices, such as a liquid crystal display device, a plasma display device, a field emission display device, an organic light emitting display device and the like have been popularly used as color monitors for computers or other information equipment, or as display devices in television receiver sets. Among these flat panel type display devices, there has been a so-called hold-type display device which operates on the basis of the light emitting characteristics of pixels. The liquid crystal display device and the plasma display device are typical examples of a hold-type image display device. For example, the liquid crystal display device displays images with the following constitution and manner of operation.
FIG. 9 is a block diagram which illustrates the general characteristics of the display panel and the driving system of the typical active matrix type liquid crystal display device. This type of liquid crystal display device includes a liquid crystal display panel PNL. Further, the liquid crystal display device includes, on the periphery of the liquid crystal display panel PNL, a driving circuit (constituted of an IC chip or the like) which drives display signal lines DL (video signal lines, data lines, drain signal lines, drain lines or simply referred to as signal lines), that is, a display signal driving circuit (hereinafter, also referred to as a drain driver) DR, and a driving circuit (constituted of an IC chip or the like) which drives display scanning lines GL (gate signal lines, gate lines, or also simply referred to as scanning lines), that is, a display scanning line driving circuit (hereinafter also referred to as a gate driver) GR.
Further, the liquid crystal display device includes a display control circuit CRL, which constitutes display control means for supplying display data DATAin for displaying images, control signals (various clock signals including dot clocks CL, display timing signals DTMG, vertical synchronizing signals VSYNC, horizontal synchronizing signals HSYNC and the like), gray scale voltages and the like to the drain driver DR and the gate driver GR, and a power source circuit PWU. The display control circuit CRL is provided with a timing controller Tcon which generates various display timing signals for controlling the display. Pixels PX are arranged on crossing portions where the gate lines GL and the drain lines DL cross each other.
The input display data DATAin that is transmitted from an external signal source (a host computer), such as a computer, a personal computer or a television image receiving circuit, and various voltage signals, such as the dot clocks DCLK, display timing signals DTMG, the vertical synchronizing signals VSYNC, and the horizontal synchronizing signals HSYNC, are inputted to the display control circuit CRL. The display control circuit CRL includes a gray scale reference voltage generating part and the like (not shown in the drawing) besides the timing controller Tcon, and it converts the input display data DATAin and the various voltage signals from the outside into output data (display data) DATAout in a form suitable for display on the liquid crystal display panel PNL. The display data DATAout and the various clock signals CL are supplied to the drain drivers DR and the gate drivers GR in the manner shown in the drawing. In such a constitution, a carry output CRY of the preceding stage of the drain driver DR is directly supplied to the carry input of the drain driver of the succeeding stage. Reference symbol DB indicates a data bus of the display data DATAout.
The liquid crystal display device having such a constitution has been steadily replacing a cathode ray tube (CRT) display due to its beneficial features, such as low power consumption. The acceleration of such replacement is brought about by technological innovations which have led to enhancement of the image quality of the liquid crystal display device. Particularly, in recent years, a demand for motion picture display, as represented by a television image, is becoming stronger, and improvements have been made in liquid crystal materials and driving methods to satisfy this demand.
However, while the CRT employs an impulse type light emission by electron beam scanning using an electron gun, as mentioned previously, the liquid crystal display device employs a hold type light emission using a backlight system or the like, in which a linear lamp (a fluorescent lamp) or the like is used as an illumination light source; and, hence, it has been considered difficult for the liquid crystal display device to produce a complete motion picture display. That is, when a motion picture display is produced using a liquid crystal display device, due to the holding characteristics thereof, so-called motion picture profile deterioration (generally referred to as “blurring” or “motion picture blurring”) is generated, and, hence, the image quality is degraded. The phenomenon is not limited to a liquid crystal display device and is generated in the same manner in a plasma display device or the like, for example.